defconfig: msm: Enable mpu based kernel text protection

Enable mpu based kernel text region protection for
msm8917, msm8937, msm8940 and msm8953. This would ensure
that any other master (than cpu) would not be able to
over-write kernel code.

Change-Id: Ib4190756987ae21dbca3dde05f47f9d9fa0319cc
Signed-off-by: Shiraz Hashim <shashim@codeaurora.org>